Electric locomotive.



No. 867,486. PATENTED 001. 1, 1907.

' s. T. DODD.

ELECTRIC LOGOMOTIVE. APPLICATION rum) r mma. 19oz.

WITNESSES) INVENTDR W P -j 'Y WWW.

UNITED STATES PATENT OFFICE.

SAMUEL T. DODD, OF SOHENEOTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

ELECTRIC LOCOMOTIVE.

Specification of Letters Patent.

Patented Oct. '1, 1907.

' Application filed February 18, 1907. Serial No. 857,905.

To all whom it may concern: v v

Be it known that I, SAMUEL T. Donn, a citizen of the United States,residingat Schenectady, in the county of Schenectady and State of NewYork, have invented certain new and useful Improvements in ElectricLocomotives, of which the following isa specification.

My inventionrelates to-electric locomotives having driving-wheels andidlers, and its object is to provide a novel arrangement forautomatically increasing the pro-.

ried on the drivers at full speed results in overheating or excessivewear of driving axles and journals.

By my invention the variation of \load distribution is made automatic,orrather, placed under the control of thesame switches that control themotors. By placing an electromagnet in the motor-circuit, which respondsto an increase of current in the motor-circuit above a predeterminedamount, and by controlling the load-shifting device by thiselectromagnet, the load is shifted automatically when the motor-currentand torque rise above a predetermined amount. The magnet is cut intocircuit by the switch which controls the motors,' and is controlledautomatically by this switch in its ordinary operation to vary thecurrent supplied to the motor.

In the accompanying drawings, Figure 1 shows in elevation one-half of adouble truck electric locomotive provided with a load-shifting deviceadapted for control in accordance with my invention; Fig. 2 shows a I ofthese pills on the equalizing links determines the'proportions of theweight of the frame carried by the driving-wheels and idlers; the weightcarried by each wheel being inversely proportional to the distance ofits axle from the pin D. F F represent levers each of which may beformed with a pin D as single forging as shown which rocks on the pin Das on a pivot, and carries another pin or projection D nearer the axleof the driving-wheel than the pin D. Pull-rods f f connect levers Y F toa rod 9 which extend across the frame and is connected to the piston ofan air-cylinder G, so that when air is admitted to the cylinder tomovethe piston toward the left, strains are placed on the levers F F,tending to rotate them on the pins D D. The pull on the right-hand leverF as viewed in Fig. 1 is in a counterclockwise direction, and on theleft'hand lever in.a clockwise direction. This pull, acting on theselevers, tends to shift the load on the links C from the pins D to thepin D thereby shifting the effective points of support on the equalizerlinks toward the driving-wheels,

and thereby increasing the proportionate weights carmission of air fromthe main reservoir H to the cylin ders G and the exhaust from thecylinders. This valve is controlled by a magnet J, which, in turn, iscontrolled by an overload magnet K placed in the circuit with thedriving motor M. This magnet is shown inserted between the trolley orcurrent-collecting device L, and the switches 0, shown diagrammaticallywhich control the supply of current to the motors M. Whenever eitherswitch 0 is moved to close the motor-circuit, current passes through themagnet K, and if the current admitted to .the motors rises above acertain limit, magnet K draws up its armature, thereby energizing magnetJ and shifting valve I to admit air from the reservoir H to thecylinders G. Thus, at starting, when the maximum traction effort isrequired, the magnet K will be energized, since the starting-current islarge; and in general, whenever current above a predetermined amount isadmitted to the motors, so as to increase their torque above a certainamount, the magnet K will be energized sufliciently to close itscontacts, and the proportionate load on their drivers will be increased.When the current falls below the predetermined an'iount, magnet K dropsits armature, do

energizing magnet J and allowing valve I to be returned to its normalposition by a spring or other suitable mechanism. The load is thusshiited automatically to meet the traction requirements, and the load- 7shifting devices require no attention from the operator; but arecontrolled in a proper manner merely by the usual manipulation of themotor-controlling switches.

I do not desire to limit myself to the particular construction andarrangement of parts here shown, but aim in the appended claims to coverall modifications which are Within the scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,

1. In an electric locomotive having driving-wheels and idler-s, meansoperative upon a predetermined variation of load on the driving motorsfor varying the distribution of weight on the wheels.

In an electric locomotive having driving-wheels and idlers, means forautomatically increasing the proportionate load on the driving-wheelswhen the motor current reaches a predetermined value.

3. In an electric locomotive having driving-wheels and idler-s, anelectromagnet in the motor circuit and means controlled thereby forvarying the distribution of load on the wheels;

4. in an electric locomotive having driving-wheels and idlers, anelectromagnet in the motor circuit, a valve controlled thereby, andpneumatically-actuated means controlled by said valve for varying thedistribution of load on the wheels.

5. In an electric locomotive having driving-wheels and idlers, anelectromagnet, a switch controlling both the driving'motors and saidelectromngnet, and means controlled by said electromagnet for varyingthe distribution of load on the wheels. I

G. In an electric locomotive having driving-wheels and idler-s, meanscontrolled by the motor-controlling switches for varying thedistribution of load on the wheels.

7. In an electric locomotive having driving-wheels and idlers,pneumatically-actuated means for varying the distribution of load on thewheels, and means controlled by the motor-controlling switches forcontrolling said pneumaticaliynctuated means.

amass 8. In an electric locomotive having driving-wheels and idlers,pneumatically-actuated means for varying the distribution of weight onthe wheels, a controlling valve therefor, and means controlled by themotoncontrolling switches for controlling said valve.

9. In an electric locomotive having driving-wheels and idlers, anequalizing link suspended between a driving wheel and idler andsupporting a portion of the weight of the locomotive frame, and meansoperative upon a predetermined variation of load on the driving motorsfor shifting the effective load-point on said link.

10. In an electric locomotive having driving-wheels and idlers, anequalizing link suspended between a driving- 'wheel and idler andsupporting a portion of the weight of the locomotive frame, and meanscontrolled by the motoreontrolling switches for shifting the effectiveload-point on said link.

11. In an electric locomotive having drivingwvheels and idlers, anequalizing link suspended between a drivingwheel and idler andsupporting a portion of the weight of the locomotive frame, anelectromagnet in the motor circuit, and means controlled thereby forvarying the effective load-point on said link.

12. In an electric locomotive having driving-wheels and idlers, anequalizing link suspended between a driving wheel and idler andsupporting a portion of the weight of the locomotive frame,pueumaiicaliy-actuatcd means for shifting the effective load-point onsaid link, and menus controlled by the motor-controlling switches [orcontrolling said pneumatically-aetuated means.

In witness whereof, I have hereunto set my hand this 15th day ofFebruary, 1907.

SAMUEL T. DODD.

Witnesses BENJAMIN B. HULL, IlnLnN ORFORD.

